Fireflies in the Snow: Observations on two early-season arboreal fireflies Ellychnia corrusca and Pyractomena borealis

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Abstract
Field studies on two cold-hardy sympatric firefly species Ellychnia corrusca complex (Linnaeus) and Pyractomena borealis (Randall) were conducted from 2008 to 2011, in East Tennessee in the southeastern United States. Their behaviours , predation events, escape strategies, calendar and degree-day parameters for life events are presented and regional differences discussed. Adults of E. corrusca and last instar larvae of P. borealis become active in February when snow and below-freezing temperatures are common. They gather in the furrows on the warmer, sunlit south sides of still-leafless preferred trees, the majority of which are large diameter oaks (Quercus sp.) for E. corrusca, hickories (Carya sp.) for P. borealis and tulip poplars (Liriodendron tulipifera) for both firefly species. Ellychnia corrusca, lanternless and diurnal, abruptly appear low on colony trees in late winter (Jan-Feb), orienting to the sun and vertically to one another upon initial emergence. A 4-to 6-week quies-cent period follows this emergence during which time they remain on their colony tree slowly patrolling or resting head down in the bark furrows. Flight, dispersal and mating occur in mid-March to April. Diurnal P. borealis larvae climb from cold winter ground up preferred trees seeking sunny, protected pupation sites. Frequent moving is common in Jan-Feb as larvae select ideal arboreal sites. Pupation takes place in March with protandrous males attaching, pupating and eclosing before most females. Adult males use two mating strategies. Initially day active, they seek out and tend both larval and pupal females for up to two weeks and attempt copulation as soon as the guarded virgin female ecloses, bypassing courtship and flashing. In the nocturnal courtship display, P. borealis males flash in flight every ca. 2 s in April on fair-weather nights above 10-12°C, high in the forest canopy. Intense male competition , repeated mating and prolonged (1-to 8-day) copulation is common.
Fireies in the snow: Observations on two
early-season arboreal reies Ellychnia
corrusca and Pyractomena borealis
L F
Emory River Land Company, 11828 Couch Mill Road, Knoxville, TN USA 37932.
Email: TNLFaust@gmail.com
ABSTRACT Field studies on two cold-hardy sympatric rey species Ellychnia
corrusca complex (Linnaeus) and Pyractomena borealis (Randall) were conducted
from 2008 to 2011, in East Tennessee in the southeastern United States. eir behav-
iours, predation events, escape strategies, calendar and degree-day parameters for life
events are presented and regional dierences discussed. Adults of E. corrusca and last
instar larvae of P. borealis become active in February when snow and below-freezing
temperatures are common. ey gather in the furrows on the warmer, sunlit south
sides of still-leaess preferred trees, the majority of which are large diameter oaks
(Quercus sp.) for E. corrusca, hickories (Carya sp.) for P. borealis and tulip poplars
(Liriodendron tulipifera) for both rey species. Ellychnia corrusca, lanternless and
diurnal, abruptly appear low on colony trees in late winter (Jan-Feb), orienting to
the sun and vertically to one another upon initial emergence. A 4- to 6-week quies-
cent period follows this emergence during which time they remain on their colony
tree slowly patrolling or resting head down in the bark furrows. Flight, dispersal
and mating occur in mid-March to April. Diurnal P. borealis larvae climb from cold
winter ground up preferred trees seeking sunny, protected pupation sites. Frequent
moving is common in Jan-Feb as larvae select ideal arboreal sites. Pupation takes
place in March with protandrous males attaching, pupating and eclosing before most
females. Adult males use two mating strategies. Initially day active, they seek out and
tend both larval and pupal females for up to two weeks and attempt copulation as
soon as the guarded virgin female ecloses, bypassing courtship and ashing. In the
nocturnal courtship display, P. borealis males ash in ight every ca. 2 s in April on
fair-weather nights above 10-12°C, high in the forest canopy. Intense male competi-
tion, repeated mating and prolonged (1- to 8-day) copulation is common.
Keywords: Pyractomena borealis, Ellychnia corrusca, daytime lightning bug, mate
guarding, pupal tending, rey, preferred trees, arboreal, aerial pupation
Lampyrid 2012. 2:4 8-71
Copyr ight © 2012 Brazen Head Publish ing. All Rig hts Reserved.
Lampyrid Volume 2 (2012)
OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 49
INTRODUCTION
In early to mid-February (late winter)
with few insects evident, two sympatric
rey species become active in the bare,
cold, oen snow-covered forests of the
Great Tennessee (TN) Valley, the Great
Smoky Mountains and the Cumberland
Mountains of East TN in the south-
eastern United States (Fig. 1). Adults
of the Ellychnia corrusca L. complex
(Fender 1970), diurnal and lanternless,
emerge and share many of the same trees
as the last instar larvae of Pyractomena
borealis Randall that climb from the
forest oor to seek arboreal pupation sites on the southern aspect of the trunks of
those trees (Fig. 2).
Both species are widespread in the eastern half of the US with the latitudinal
range extending south from southeastern Canada to north central Florida (FL), a
distance of more than 2200 km (Green 1957; Fender 1970; Bousquet 1991; Lloyd
1997; Rooney & Lewis 2000) (Fig. 1). Initial natural history observations were
recorded for both species almost a century ago by Williams (1917). Pyractomena
borealis preimaginal larval descriptions are reported by Archangelsky and Branham
Figure 1 East TN sites (white circle: TN).
North-south range (red arrow) of both
Pyractomena borealis & Ellychnia corrusca
complex.
Figure 2 Ellychnia corrusca (A) and Pyractomena borealis (B). Note the pale elytral margin of
the latter.
A B
Lampyrid Volume 2 (2012)
50 FAUST
in 1998. Buschman (1984) describes the transformation of the prepupal pygypod
(moveable tail organ) to a permanent anchor-like organ in the closely related P.
lucifera. Aerial, arboreal pupation behaviours, such as tree positioning to inu-
ence microhabitats (Lloyd 1997), pupal development rates and protandry (Gentry
2003) are provided for the semi-tropical FL P. borealis (877 km south of TN). Cooler
Massachusetts climate (1324 kilometers north of TN) E. corrusca adult wintering
and mating behaviours and survival rates are described by Rooney and Lewis
(2000). Like many temperate region reies, E. corrusca and P. borealis have well-
dened seasons of appearance and peak activity (Faust 2004, Faust & Weston 2009).
In East TN, adults of E. corrusca appear in Jan-Feb and are rarely seen aer May;
the last instar larvae of P. borealis also appear in February with few adults seen aer
April. Local species representatives can be found in the Great Smoky Mountains
National Park collection (GSMNP), Gatlinburg, TN (Mayor 2006).
Active in the daylight and oen found below 3 m on tree trunks, the adults of E.
corrusca and larvae of P. borealis are easily accessible for live studies in their natural
habitat before the other common fourteen-plus East TN species (Faust & Weston
2009) emerge. Both rey species appear to return to the same or nearby trees
each season. ese reies, widespread but less abundant than other local rey
species, are found in loose colonies on the margins or within the secondary, mixed
hardwood forests of East TN, which are predominantly Appalachian oak-hickory
type (Fig. 3).
is longitudinal study, spanning four years of focused studies and 19 years of
eld observations, documents the continuity and stability of these populations and
presents emerging threats, particularly to the Knox County population which was
the primary study site.
e study site habitats shared by both species are described together. e species
details are dealt with separately. Regional dierences and similarities are discussed
and new information presented on selection behaviour (of host trees and direc-
tional orientation), aspects of development (life event dates, mortality factors and
survival rates) and reproduction (sex ratio, larval/pupal seeking and tending, mate
guarding, ashing and mating). Average calendar dates and modied growing
degree day values (mGDDC) for life stage landmarks (Faust & Weston 2009) are
oered when signicant as a reference point for future comparisons to far distant
populations. is paper was presented at the August 2010 Malaysian International
Firey Symposium. New data from the 20112012 season has been added to augment
the results reported at that meeting. It is hoped this information will further the
understanding of these adaptable early season species.
METHODS
Study sites
ere were ve study sites in East TN, USA, i.e. Knox (35°56’38.13”N 84°12’15.97”W,
Lampyrid Volume 2 (2012)
OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 51
274-305 m a.s.l.), Blount (35°36’55.05”N 83°40’07.32”W, 640 m, GSMNP), Sevier
(35°39’02.79”N 83°34’32.33”W, 731 m, GSMNP), Jeerson-Grainger (36°06’23.64”N
83°37’58.11”W, 305 m) and Morgan (36°12’11.52”N 84°35’17.14”W, 407 m). Fireies
of both species have been found at these sites every year since I started observing
them in 1992. Knox County, the primary site, was 46–66 km from the other four
sites. e Knox site consisted of a 4.3 km circular loop covering 15 ha of maturing
species-diverse (i.e., more than 111 species) Appalachian oak-hickory type secondary
forest (Oswalt 2007) that borders privately and publicly owned lands (Fig. 3). e
four secondary sites are generally similar in habitat and forest composition, but the
two GSMNP sites are higher in elevation (Faust 2010) and the Jeerson-Grainger
site includes an alluvial oodplain forest. Using ve sites enabled comparing the
reies’ tree usage and emergence patterns in slightly varying habitats within the
same region. Within the sites, Ellychnia corrusca colonies have been found at the
same locations every year and while there may be slight shis in trees used, the
number of trees occupied is fairly consistent. At Knox, the main colony occupies 29
trees located on a 0.5 ha karst hilltop rim while a smaller colony is found on 2 trees
0.5 km away. e circular 0.37 ha Blount site has a large colony occupying 20 trees
and a smaller colony on 6 trees 1 km away.
Field sampling
e studies for the two rey species took place over four seasons (2008–11). Outside
the rey season from May–January, monthly site visits recorded sightings of adults
or larvae on trees or the ground. e sites were visited weekly from the rst appear-
Figure 3 Preferred trees (9 species) utilised by Ellychnia corrusca and P yractomena b orealis in
relation to the composition of a typical Appalachian oak-hickory forest with ≥111 species.
Lampyrid Volume 2 (2012)
52 FAUST
ance of E. corrusca, in Jan or Feb through early May (last sightings for P. borealis).
During the rst few surveys for each rey species, the season’s colony trees were
identied and marked. Colony trees of previous years were checked rst, followed
by neighbouring trees. In the rst year of this study, P. borealis exuviae persisting on
trees used in 2007 identied previous colony trees for that rey species. Searches
for additional colony trees within the sites were carried out each season. For all
colony trees, the following were recorded: species, diameter at breast height (dbh),
height, vertical position in canopy layer (canopy or understory), bark characteristics
(smooth, scaly, rough or furrowed; if furrowed, depth of furrow measured), and
location in relation to amount of solar radiation received (sunny or shaded).
Surveys at secondary sites were not continued if fewer than ve individuals were
found during the rst weeks of emergence for that particular species. In addition
to the weekly site visits, the primary site (Knox) was visited 1–3 times daily from
the week of rst appearance. For both rey species, site visits recorded the number
of individuals found on each of their respective colony trees. For each individual,
the following was also recorded: height from the ground; orientation in relation to:
1) aspect on tree (i.e., amount of solar radiation received, where the south-facing
side is warmest),
2) the vertical line of the tree trunk,
3) other individuals; activity level (slow or fast-moving); sex (of adults for E.
corrusca, when possible and at the pupal/adult stage for P. borealis). Aspects
of behaviour during primary life events were recorded (quiescence, escape
strategies, dispersal, mating and oviposition for E. corrusca; escape strate-
gies, pupation, pupal-guarding, eclosion, courtship and mating for P. borealis).
Mortality and likely causes were recorded, and also the presence of other insects
resembling these reies.
As P. borealis courtship displays commenced at Knox, nightly walks along the
loop trail were made to record the relative number of individuals in the treetops.
Individuals could be reliably counted by their ashes because they usually ashed
more than 5 m apart from their nearest closest neighbours. Towards the end of
the courtship period as the trees leafed out (thus obstructing canopy view from
beneath), ash counts were made from the creek bordering half the loop.
Additionally, in 2011 at Knox and Blount, all E. corrusca sighted were marked on
their elytrae with distinct individual patterns of colour/dots/dashes with non-toxic
ink (Uchida DecoColour™) identifying them by colony tree on the date they were
rst sighted. Daily (visual) recaptures were carried out to determine their movement
(if any) to other trees. Live elytral length was measured using a Mayo™ caliper and
ruler. Also in 2011 at Knox, about half of all P. borealis larvae sighted and later, all
eclosing adults, were likewise marked and recaptured (visually) daily. Over the 4
years, random live measurements of larvae, pupae and adults were made to deter-
mine general live size ranges.
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OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 53
Accumulated modied growing degree-day (mGDD) values, also known as
30/10 C (or 86/50F corn growing degree days in US) and daily temperature data,
were obtained from National Weather Service (NWS) station #406742 for all study
sites except the higher elevation Sevier and Blount sites which used NWS #316341.
For more complete explanation of this heuristic tool as it applies to reies and
data tables see Faust and Weston (2009) and Fridley (2009), and the regional and
federal climate centre microclimates websites (NRCC 2008-2010; NOAA 2008–10).
Air temperatures were measured frequently and randomly comparing the microcli-
mates of the south- and north-facing sides of colony and preferred trees.
Laboratory and controlled eld studies
In 2010, E. corrusca adults (ve males and ve females) and a larva (a rare nd) were
observed in captivity for a week in April and September–October, respectively. e
adults were placed in a mesh-capped two-litre glass jar lined with native soil and a
few twigs positioned vertically. e larva was found glowing in the soil below leaf
litter by a gravel road at Sevier at 9 pm, 23rd September.
In 2008 and 2009, separate mesh enclosures were put around four P. borealis
female pupae where they were attached to their colony trees in order to determine
when they rst spontaneously ashed at males or articial ashes aer eclosion. Two
captive virgin females were observed in 2008 and 2009 for copulatory behaviour
and times. In 2011, 8 female and 5 male pupae were collected within several days
of predicted eclosion and placed in natural position, pygypodia taped to sticks, in
1 quart mesh covered containers in a covered outdoor setting, within their habitat.
Once eclosed, these 13 virgin adults were observed for 14 days for copulation events
and times and remating behaviours and times. Two additional wild caught males
were added to the remating studies the nal week. Apple slices were provided as
food. Aer 2-3 matings, females were returned to their pupal trees in order to
preserve the local population. Males were either released at night or kept until death
to determine typical male lifespan. Representative specimens of E. corrusca and P.
borealis from this study are deposited in the Florida State Collection of Arthro-
pods, Gainesville, FL. Photographs were taken with a Kodak Z740 Easyshare or an
Olympus Stylus 720 and 770SW.
RESULTS
Life events of Ellychnia corrusca
Morphology
Like many diurnal reies with no lanterns, E. corrusca lacked paler elytral margins,
yet retain the bright red and pale yellow markings on their wide (3-7 mm) prono-
tums (Fig. 2). e ridged dorsal elytral surface was densely covered by yellowish,
olive green hairs. In the eld, both sexes looked similar. Size and pronotum colour
Lampyrid Volume 2 (2012)
54 FAUST
variation was common. e body and elytral
length of specimens from Knox (16.2 mm ±
1.3 and 11.9 ± 1.1 mm, respectively; n = 19)
were greater than the higher elevation (731
m, 640 m) Sevier and Blount adults (12.9 ±
1.7 mm and 9.4 ± 1.4 mm, respectively; n =
44). Females from 9 - 17 mm in size were
seen coupled to males 9 mm in size (Fig. 4).
In 2010, three of 164 newly emergent adults
had bent or damaged elytra.
Larvae
Robust, dark bodied Ellychnia corrusca
larvae, rarely seen, were covered in bristly
coarse setae. One glowing larva, found in
September, white and pink from recent
molting, had darkened by the next morning
(Fig. 5). It measured 15–17 mm long and
3.5 mm wide and readily ate small chopped
live worms 6 times in 21 days. It used its
pygypodia (caudal tail organ) for grooming
and to pry open a fresh water snail operculum. It did not attack a more fragile
Photinus sp. larva kept in the same enclosure. ey oen fed together, though the
Photinus larva deferred to it. Aer six weeks, it died from unknown causes.
Abrupt appearance and vertical emergence of adults
From late October to early February, few to no adults or larvae were evident either
on the ground or tree trunks. Adults were rst sighted at one or more of the sites
on 14, 10 and 18 February in
2008, 2009 and 2010, respec-
tively, and on 20 January in
2011. At Knox (29 trees) in
2010 (Fig. 6), no adults were
seen until 20 February when
44 were found. e next day’s
total was 104. Smaller groups
emerged over the nal week
in February, usually on clear
sunny days, with a late group of
seven appearing on 29 March
bringing to a total of 217 adults
for that site and 299 for all sites.
Figure 4 Ellychnia corrusca complex has
large size variation. Coupling occurs on
trees by day.
Figure 5 Ellychnia corrusca late instar larva feeding on a
fresh earthworm section.
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OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 55
When emerging at temperatures below 5°C, oen with snow-covered ground, the
adults moved slowly. Mean height up the tree trunks increased daily from 66 cm (on
18 February) to 88 cm, 152 cm, and 170 cm on Feb 21 (range 15-152 cm, 22-243 cm,
96-307 cm, 0-320 cm respectively) at the Morgan and Knox sites with temperatures
at appearance ranging from 0-16°C.
ey were oriented facing a southerly direction (mean 182 ± 21°, n = 299) on
the trees, and on each tree were vertically oriented to one another (Fig. 7). In 2010,
at Knox, over 95% of 217 adults followed this
vertical orientation to one another. e rest
appeared scattered but still climbing the south-
erly aspect of the trees. On subsequent days, the
vertical arrangement disappeared as the majority
of adults scattered and climbed out of sight up
the trees. In 2011, at Knox and Blount, 90% of
the nal tally of adults (n = 123) emerged more
gradually from 29 January – 1 March with peak
numbers reached by mid-March. Orientation
was 189 ± 19°.
e 2012 season had an unusually mild winter
and early spring. First E. corrusca emergence of
30 climbing adults was observed on 29 December
2011 at the Blount site, with subsequent dates
of dispersal and coupling beginning 2-4 weeks
earlier than previously recorded (by 19 March).
Colony trees
From 2008-10, oaks (Quercus velutina, Q. alba
and Q. coccinea) and tulip poplars (Tulipifera
Figure 6 Visible presence of Ellychnia corrusca adults monthly for one year at Knox Co. colony,
in ight from July 2009 - June 2010 and on trees from July 2009 - April 2010.
Figure 7 Ellychnia corrusca, six
adults circled in black, abrupt
appearance in February with group
vertical tracking up the colony tree.
Lampyrid Volume 2 (2012)
56 FAUST
liriodendron) were colonised by 87% (n = 241) of adults. ese tree species comprise
only 16% of the total forest composition of trees >2.5cm dbh (Oswalt 2007). At
Knox, in 2010 and 2011, 83% (n= 29) and 80% (n = 10) of the colony trees, respec-
tively, were oaks while at Blount, 84% (n = 26) of trees colonised were tulip poplars,
which are abundant there. Colony trees, 60 to 80 years old, were mature, living
and dominant canopy trees found in open deciduous forests. ey shared direct
exposure to winter sun for most of the day, had rough, furrowed or scaly bark
(furrow depth 12 ± 3.6 cm, n = 27), were canopy (25m+) trees and relatively large
dbh (57 ± 16 cm) compared to the many other tree species in the surrounding forest.
From 2008-2011, lightning, high winds and disease killed 4 of the colony trees.
Quiescence
e quiescent phase was from rst appearance to mid-March (Table 1). e adults
oen rested head-down in south facing bark furrows, with no apparent vertical
orientation to one another. ey were minimally active (crawling) on any sunny
above-freezing day. Marked adults (n = 123) in the recapture study frequently moved
up and down the trees, as much as 3 meters in 30 minutes especially on sunny days.
Up to 24 days aer the rst sighting, 96% of the 54 recaptured adults were on their
original tree. e remainder were on nearby trees (< 3 m away), having dropped to
the ground and disappeared when initially marked (which threatens them). In the
nal 2-3 weeks of quiescence before dispersal, no recaptures were recorded at Knox
and fewer than twelve were sighted at Blount. ey may have climbed up into the
colony tree canopies. Few were seen in late quiescence until ight, dispersal and
coupling began. In 2012, adults were visually recaptured as long as 66 days past
initial marking.
Dispersal, mating and ovipositing
Dispersal, recognised by the reappearance of reies in ight or active on both
colony and non-colony trees, occurred in mid-March at air temperatures above
15°C. First observed ight in 2010 and 2011 was on 8 March at 20°C and 17 March
at 23°C, respectively. On very sunny days where south-facing trunk temperatures
1 Early June for high elevation.
Table 1 Ellychnia corrusca general life cycle calendar, East Tennessee.
Larva e/
occass ional
adult
Few or no
Ellychnia
evident
Emerge &
climb tr ee
Quiesce nt on
tree tru nk
Flight /
dispersal
Couplin g /
ovipositing
Adult / deat h
May -
November
June -
January
February -
early March
February -
mid March
Mid - late
March
April Late April -
early May1
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OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 57
exceeded 25°C, adults were oen seen on the north sides of the still-leaess trees
where temperatures were 5-10°C cooler. From 2008-11, coupling started in April
within 119-222 mGDDC (215-400 mGDDF), regardless of warm weather before
that time. At Knox and Sevier, the most active coupling period in 2010 and 2011 was
9-10 April (10 couples and 11 singles recorded) and 29 March – 9 April (11 couples
and 49 new unmarked singles recorded), respectively. In 2011, 23 and 19 colony and
non-colony trees, respectively, were used for courtship and coupling. Mating was
not observed on the ground. Flying individuals were most oen seen aer 12 noon
when it was warmest. By April’s end, few remained and no coupling was observed
at Knox while at Sevier, small numbers (<10) persisted through the rst week of June
in 2009, 2010, and 2011. From June-Dec, adults were rarely seen (Table 1 and Fig. 6).
In the laboratory, multiple matings between the 5 males and 5 females were
observed for both sexes, in Stage 1 and 2 positions (see Lewis & Wang 1991). Coupling
(9 observed in 7 days) took place vertically on twigs when available (otherwise on
the soil), commencing before sunrise and lasting 2 to more than 6 h. Females laid
o-white eggs measuring 0.5-0.9 mm (n= 27) singly in the soil on successive days.
Under magnication, the egg surface appeared slightly rough and sticky.
Escape strategies
When observed too closely or feeling threatened, their two primary escape strate-
gies were actively crawling up the trunk or dropping to the ground on their backs,
becoming well-camouaged in the leaf litter. Escape climbing took place even on
cold (<0°C) days, albeit slower than on warmer days (especially >20°C). When
marked, they exhibited distress by dropping to the ground, opening and closing
their elytra or attempting to rub their bodies on the bark. When handled or when
crawling, they oen deposited a clear droplet of liquid from their terminal segment.
ey exuded white beads of reexive bleeding from the elytral margins when
severely threatened. Flying, observed only aer dispersal, was seldom used as an
escape strategy.
Figure 8 Left to right: A white phorid (Apocephalus antennatus) larva emerges as its female
Ellychnia corrusca host dies; phorid pupae; adult phorid. Phorid ies are parasitoids of E.
corrusca and Pyractomena borealis.
Lampyrid Volume 2 (2012)
58 FAUST
Predation and mimics
Predation was recorded early (28 February) in the season for 2010 and 2011 and
parasitism late (22 April) in the 2011 season. In 2010, two of four males taking
shelter in a hole at the base of a Quercus alba tree were preyed on and in 2011,
three unmarked elytra were found at the base of colony trees in thick leaf litter. Bite
marks and/or tears on elytral remnants were consistent with rodent or bird preda-
tion. In 2011, 32 phorid larvae (Brown 1994) that emerged from a female that died
shortly aer, were later identied (Brown, pers. comm.) as Apocephalus antennatus
Malloch (Diptera; Fig. 8). Beetles and moths from several families with mimic-like
colouration and patterns were oen found on or near the rey colony trees (Fig. 9).
Figure 9 Mimicry complex on/near trees colonised by Ellychnia corrusca and Pyractomena
borealis: 1-5. Cantharidae (8-12 mm); 6. Lycidae (9 mm); 7. Meloidae (6 mm); 8. Lampyridae (E.
corrusca on top, 15 mm; P. borealis beneath, 17 mm); 9. Carabidae (15 mm); 10. Pyrochoidae (12
mm); 11. Silphidae (20 mm); 12. Cerambycidae (9 mm); 13-14. Arctidae (20 mm); 15-17. Elateridae
(10 mm); 18. Pedilidae (7 mm).
Lampyrid Volume 2 (2012)
OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 59
Life events of Pyractomena borealis
Fall larvae
Over the four years, a total of ve late instar larvae were observed in September and
October (outside the P. borealis season). ey were found glowing intermittently on
leaf litter and vegetation up to 20 cm from the ground.
Climbing-searching larvae
e rst sightings of last instar, searching-climbing larvae occurred during the day
on 1st March, 10th, 20th and 21st February in 2008-11, at temperatures of 12°C,
10°C, 16°C and 19°C, respectively. In the very mild winter of 2012, larvae climbed
over a month earlier (Jan 22), rst ashed and fully eclosed up to 3 weeks earlier
(19-25 Mar) than previous years. Male larvae climbed-searched 15 ± 8 d (n = 68,
2008-11) earlier than the females (n = 40). e pink-tinged larvae measured 16-26
mm (live length, n = 20). ey were narrow-headed, cryptically coloured, mottled
light yellow to dark brown. ey climbed up from the leaf litter and actively investi-
gated the south-facing furrows low on the trunks of their chosen trees. ey got no
higher than 1 m up the trees in the earliest searching phase in February and oen
disappeared early in the season. On very cold days (< -8°C), they remained motion-
less in the furrows. ey relocated every few days in search of more southerly or
protected sites.
By early March they were head down with dorsum facing outward, and had
begun to anchor their pygypodia within the furrows or under bark scales (Figs. 10
& 11). Four pupated ‘backwards’ with the dorsum facing the tree and/or (exposed)
outside the furrow. Anchoring was oen permanent within 3 days. Larvae disturbed
in the rst two days were found to abandon the site (12 of 21 larvae moved when
marked in 2011) instead of going on to pupate. Once attached, if disturbed, they
glowed and arched backwards and up.
e pupation sites were at a mean height of 147 ± 46 cm (n = 107) and oriented
at 170 ± 23°. In 4 years, the lowest pupation site was 28 cm and the highest observed
was 300 cm. Males pupated 12 ± 7 d (n = 68, 2008-11) earlier than females (n =
40) but their pupation heights appeared no dierent. Mean furrow depth for these
pupation sites was 10 ± 3 mm (n = 53).
Relative temperature measurements taken randomly at the actual pupation sites
throughout the rey season averaged 16°C (n = 320) compared to the opposite,
shadier side of the trees, which averaged 14°C. On sunny days before the trees leafed
out, the temperature dierence between the north- and south-facing pupation sites
oen exceeded 13°C.
During the larval climb and pupation period, temperatures ranged from -1°C to
31°C. e range for pronotal width was 4-7 mm and body length was 11-26 mm (n
= 45), with the largest larvae and pupae (22-26 mm, n = 21) eclosing into the largest
female adults (20-22 mm).
Lampyrid Volume 2 (2012)
60 FAUST
Pupation
By early April most of the larvae had pupated into the characteristic black pupae
with larval exuviae still attached to the pupal dorsum (Fig. 10). Two pupae at
pupation sites that reached extraordinarily high temperatures of 42°C (on 17 April
2010) failed to eclose. e two pupae that pupated backwards and outside a furrow
did not eclose but the two that pupated in exposed locations did eclose.
Eclosion
Males began to eclose late in March, 9 ± 7 days (n = 68, 2008-11) earlier than the
females (n = 40). e sexes could be dierentiated by their lanterns (Fig. 12). On cold
days with inclement weather (< 5°C), newly-eclosed adults stayed next to their pupal
exuviae for up to 24 h as they hardened and darkened while on hot days (> 25°C),
they quickly moved to a shadier location on the trunk.
Among the marked larvae in 2011, males and females began to eclose on 27
March and 3 April, respectively. By 8 April over 50% of the females (n = 15) had
eclosed, with the last male and female eclosing 9 April and 14 April respectively,
bringing to a total of 35 males and 15 females (Fig. 13). All were re-marked soon
aer eclosing. Eight males disappeared aer marking, but the other males remained
on their pupation trees. ere was no ashing from these rst-eclosing, day-active
searching males for over a week. ese males, diurnal at this stage, methodically
searched the trunks for larval or pupal females by day and rested motionless in
furrows at night (Figs. 10 & 11). Every pupa, furrow or scale 3 m up the trunk was
investigated. Upon locating a female, the male clasped her with his legs, pressed his
Larva Pu pa Adult eclos ing guarding pupa C oupling
Figure 10 Life stages of Pyractomena borealis. Protandrous males guard female larvae and
pupae and attempt coupling as female ecloses.
Lampyrid Volume 2 (2012)
OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 61
pronotum to hers and became motionless. Pupae, when approached by a potential
guard male, arched back and forward rapidly (12 times in 2 min in one instance)
before being clasped and subdued by the male. A few male pupae (2 in 2011) were
guarded, but only briey (0.25-3.00 h). All pupae guarded for over a day eclosed
as females (2008-11). Competing males piled on top, grappled with, and oen
displaced the guard male, which would then be forced to search for another female
pupa. Males also used their pronotum to pry under or push away other males.
is competition intensied as females approached eclosion, with frequent power
reversals occurring among the increasing numbers of males. Female pupae 24 h
from eclosing had 3-7 males competing for them (n = 9).
From 2008-11, 79.1% (n = 43) of larval and pupal females were guarded by one or
more males from 1-14 days until eclosion (Figs. 10 & 11), which took about 30 min.
From 2008-11, 74.6% (n = 150) of eclosing adults were males and this male-biased
sex ratio was signicant (p<0.0001, exact binomial test). Preliminary molecular
studies on this local population found no evidence of Wolbachia bacteria (Werren
et al. 1995) as inuencing this ratio (F. Vencl, pers. comm. 2011) as has been found
to occur in some Korean rey species (Jeong et al. 2009).
Adult live mean body length, elytral length and pronotal width was 17 ± 2 mm,
11.5 ± 1.4 mm and 4.5 ± 1.2 mm, respectively (n = 58). Females, with distended
abdomens protruding 2-4 mm beyond the elytrae, oen measured longer than
males (20.1 ± 0.9 mm, n = 9 vs. 15.8 ± 1.7 mm, n = 35). Elytral length was more
similar: males 11 ± 1.2 mm; females 12 ± 1.6 mm (Fig. 12). In 2011, three of 88 newly
eclosed adults had deformed or missing elytrae and/or wings. is amount of defor-
mation was representative of previous years.
Figure 11 Pyractomena borealis males tend female larvae (A & B) and pupae up to two weeks
before eclosion. Disturbed males may abandon the female, but return when threat is gone.
Two and four males (C & D), some marked, grapple over a female pupa.
A B C D
Lampyrid Volume 2 (2012)
62 FAUST
Display and mating
Typically, a newly-eclosed (still
white and so) female (n = 18),
would be mobbed by her guard
and competing males. She would
rapidly leave her pupation site,
seeking cover under a bark scale
or crevice, with 1-3 males riding
her back. Copulation commenced
before her elytra had hardened and
darkened and no ash dialogue was
involved (Figs. 10 & 11).
From 2008-2011 rst ight and
ashing started on 10th, 12th, 11th
and 6th April respectively aer half the females had eclosed and climbed up the tree
disappearing in the canopy. In 2011, males then ceased patrolling the trunks and
even stopped guarding remaining pupae, decreasing from 46 guard males to 2 by 12
April with one female pupa le. Males displayed high in the bare or newly leafed-
out treetops, from 30 min aer sunset till sunrise with peak display 45-90 min aer
sunset. Temperatures were 14-22°C during display times. Peak nights recorded
50-120 observed individuals along the 4.3 km trail, showing that this species,
though common in dark forest habitats, is not abundant. ree ash patterns were
observed. e most common was the male’s single 0.3-0.5 s ash every 2-3 s. ey
ashed as they ew slowly around the canopy margins. Less common was the ash
pattern similar to the rst, but with the lantern dimly lit in between ashes. e
Figure 12 Lantern of male and female Pyractomena
borealis. Two lanterns on the male and four smaller
lanterns visible on the female.
Figure 13 Pyractomena borealis male and female eclosion, pupal guarding and display dates
for 2011. Note cool spell <10°C, with little activity, typical for this time of year, between 24
March and 2 April.
Lampyrid Volume 2 (2012)
OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 63
rare female seen ashing (n=7, in the wild and in captivity) responded immediately
aer the male ash with a single or bimodal ash lasting ca. 0.70-1 s, with the initial
ash brighter.
In the controlled eld study, the 4 newly eclosed virgin females did not respond
to articial or male ashes until the third night aer eclosion. In the 2011 mating/
remating studies, the 8 virgin females were not initially receptive to the advances of
males introduced to the cage. Females ed, squeezed into crevices and tucked their
tails under their bodies when pursued. Despite this avoidance behaviour by the
females, males ultimately copulated successfully in 14 of the 16 observed matings
in captivity, but less oen in the wild where the female oen escaped the pursuing
male (unquantied pers. obs.) Copulations from 2008-2011, usually remaining in
Stage 1 position (Lewis & Wang 1991), lasted an average of 67 ± 64 h (n=17) (range
3-214 h), with mean virgin pairings lasting 66 ± 62 h (n=11) and mean re-matings
lasting 84 ± 74 h (n=5). Males stayed in copula even when probed or misted with
water. Once copulation began, competing males le. If a new male arrived, brief
skirmishes occurred as he tried to take the female, but did not succeed. Both males
and females re-mated readily (n= 8). Aer copulating, the males glowed continu-
ously. When released at the base of their colony trees, they continued glowing, but
aer 5 min switched to the characteristic ash pattern, all the while climbing up the
trees. In the controlled eld study, the rst male to eclose guarded 2 females for 9
days, coupled for 65 h in captivity with a third and died on the 24th day. One of the
last males to eclose also survived 24 days, guarding 3 females for 5 days and mating
twice (160 h). Females, when returned to their pupal tree (placed on the ground near
the tree), sought the tree and climbed upward. One female with an extraordinarily
distended abdomen climbed to over 5 m, ew down to a nearby maple and disap-
peared in the new foliage.
Predation and parasitism
In 2011, three newly-anchored larvae were preyed on as evidenced by remnant
anchored pygypod stumps. Possible predators were rodents, birds and spiders. From
2008-10, 14 of 94 pupae (15%) died. Twelve were eaten by spiders. A Johnson jumper,
Phidippus johnsoni group, and the star bellied orb weaver, Acanthepeira stellate,
were observed eating pupae and newly-eclosed adults, and leaving silk-wrapped
body parts attached to the tree. Some partially-eaten pupae survived to eclose albeit
with deformed elytrae and pronotums. From 2008-10, 17.4% (n = 132) of the larvae
and pupae did not progress to adults. A pupa that fell naked to the ground aer its
exuvia was eaten by an isopod woodlouse, Porcellio scaber, successfully eclosed as
a male 7 days later in the laboratory. Phorids, Antennatus apocephalus (Lloyd 1973,
Fig. 8) parasitised adults from 2008-11. Predator Photuris reies were not a signi-
cant threat to these early season reies as local Photuris were not active until May.
Mimics were abundant throughout the display season (Fig. 9).
Lampyrid Volume 2 (2012)
64 FAUST
Dates and degree-days
From 2008-11, over half the nights in April had cold (< 12°C) or inclement weather
(e.g., Beaufort wind force 3+, rain, snow) unfavorable for ashing display. e larval
climb appeared related to relatively warm sunny days in February. Degree-days,
were useful for prediction of pupal and adult life stages and maximum display
days (Faust & Weston 2009). From 2008-11, both sexes combined (n = 78) averaged
eclosion on April 10 or aer 16 ± 5 days of pupation or 86 ± 16 mGDDC from pupae
to adult. e 18-year average for the occurrence of ash display behaviour at Knox
was 19 March – 24 April, mGDDC 119-234. Weather is extremely variable in April
e.g., 5 mGDDC/day in 2008 and 2009, and 7 mGDDC/day in 2010 and 2011, which
is seen in the varying pupal durations in calendar days, but more constant durations
in degree-days (Table 2). e higher elevation Sevier site had a later season with later
calendar dates but similar degree-day ranges.
Pupation trees
Pupation trees had certain traits: scaly or furrowed bark (10 ± 3 mm, n = 53), tall
(21-30 m), larger dbh trees (49 ± 14 cm, n = 73) with direct southern exposure to
the sun (located at forest margins or open gaps). Tulip poplars, hickories (Carya
pallida, C. cordiformis, C. glabra and C. tomentosa) and walnuts (Juglans nigra)
were used by 84% (n = 179) of the larvae; several oaks (Q. velutina, Q. alba, Q.
phellos and Q. bicolour) were used by 6%; three other tree species (pine: Pinus
virginiana; persimmon: Diospyros virginiana; and winged elm: Ulmus alata) were
used by 2.5%. Two 60 year-old Eastern Red Cedars (Juniperus virginiana) with
an abundance of stringy bark on smooth trunks, were the rst record of that tree
species as a pupation tree for P. borealis. ese cedars held eight pupae in 2011. Of
the 20 trees at Knox used in 2008, 18 were reused 2-4 seasons. In 2011, 4 of 18 trees
Table 2 Pyractomena borealis rst-sighting life-stage landmark date and degree-day range for
2008, 2009, 2010, 2011 for Knox, Jeerson, Morgan, Sevier Co., TN. One day = 3 yr. mean of 6.5
mGDDC in April. * 2012 larval climb and rst ash included. Average durations for total popula-
tion provided in tex t.
First Larval
climb*
First pupa First male First female First ash* Peak
display
<10%
Remain
Jan 22 -
Mar 1st
Mar 4th -
25th
Mar 22nd
-Apr 8th
Apr 3rd -
11th
Mar 19th -
Apr 12th
Apr 14th -
22nd
Apr 24th -
May 2nd
mGDDC
0-1.4
mGDDC
18-59
mGDDC
103-152
mGDDC
134-174
mGDDC
125-176
mGDDC
218-267
mGDDC
307-330
mGDDF
0-2.5
mGDDF
32-106
mGDDF
184-272
mGDDF
239-310
mGDDF
225-315
mGDDF
397-477
mGDDF
549-589
Lampyrid Volume 2 (2012)
OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 65
were new. Since 2008, 62% of preferred marked trees (n = 74) had one pupa, 37%
had 2-7 pupae and 1% had 8-37 pupae. A lone sand hickory C. pallida surrounded
by choking kudzu Pueraria lobata sheltered 37 pupae in 2011, the most observed
pupae per one tree.
DISCUSSION
Trees used
e occurrence of both rey species on particular tree species is likely due to
preferential selection as these tree species are not the most abundant and comprise
less than 16% of the tree species in these forests (Oswalt 2007) (Fig. 3).
In congregating Asian rey species, GPS data on specic trees known to
attract mating congregations is being documented by the Malaysian Nature Society
(Mubah 2010), the Forest Research Institute Malaysia (FRIM) and others for the
rivers of Sarawak and Malaysia (Nada et al. 2009; Wong 2009; Jusoh et al. 2010;
Ohba & Wong 2012) and reects the growing understanding of the critical impor-
tance of preserving larval habitat and preferred trees, and educating the public of
this precious resource in both the East and West.
For the TN reies, which occupied rough-barked, large diameter trees whose
trunks received plenty of sunlight, tree selection may be based on availability of
trees that provide the most favorable conditions for the reies. Similar ndings
and conclusions were reported by Rooney and Lewis (2000) for E. corrusca adults
and Gentry (2003) for P. borealis larvae in FL; (in contrast, see Lloyd’s 1997 report of
preference for smooth-barked trees). e mass of the larger diameter trees combined
with south-facing, exposed trunks of the trees provide warmer spots needed for P.
borealis larvae early in the season when it is very cold, while deep bark furrows
provide shelter from rain, snow and wind and other weather extremes.
Calendar days and degree days
Because both species range over 2200 km north to south across the eastern US and
parts of Canada, use of degree-day ranges combined with traditional calendar date
ranges could be a more accurate method of determining local seasonal appearance
regardless of population location.
As evidenced each year including during the record breaking warmth in 2012,
rey life stage dates in calendar days can vary by 3-4 weeks (Faust & Weston
2009), but the degree day ranges remain more constant, even in the record breaking
warmth of 2012. Ellychnia corrusca appeared less inuenced by accumulated
degree days, though their coupling season was not reached until at ca. 100 mGDDC
accumulated, despite periods of warmth earlier in the season.
For P. borealis, both average calendar dates and mGDDs were useful in predicting
when certain life stages (pupal duration and eclosion by sex and peak display/court-
ship) would occur and when the season would end (Table 2). Increasing survey
Lampyrid Volume 2 (2012)
66 FAUST
frequency during the predicted times for those life events helped capture impor-
tant information that may otherwise have been overlooked. Using degree-days as a
prediction tool could guide well-timed collecting eorts when limited by National
Park regulations and prevent over-collecting small local populations.
Predation and parasitism
Adults of E. corrusca suered early winter losses to probable rodent activity as
evidenced by the elytral remnants with bite marks found at the base of the colony
tree. In the milder winters of East TN, rodents such as mice and shrews are active
year-round and could pose a threat especially to E. corrusca near the ground. Rooney
and Lewis (2000) also found elytrae at the base of colony trees and suspected rodent
activity. e abrupt vertical emergence of the TN E. corrusca could help minimise
losses to rodent predation by allowing the reies to quickly ascend en masse up the
trees and away from the leaf litter. For P. borealis, the higher pupal losses to spider
predation and no (observed) predation of larvae raises the question as to why this
disparity exists. Larvae have chemical defenses (Lewis & Cratsley 2008) but it is
not known whether the same is true for the pupae. Early emergence in TN appears
to be an eective strategy by both rey species to avoid predation by Photuris
reies, which become active later and are important predators of P. borealis adults
elsewhere (Buschman 1974). Phorid parasitism of both species appeared to increase
as the season progressed (Fig. 8).
Additional discussion for Ellychnia corrusca
ese reies appear to overwinter as either adults or pupae somewhere other than
on exposed tree trunks and make a sudden initial appearance at the base of the
tree (and then climb up) during the rst relatively warm days of Jan-Feb, despite
more below-freezing weather being a certainty at this point of winter. In contrast,
the Massachusetts (MA) E. corrusca adults much further north, overwinter on the
trunks of their black oak colony trees (Rooney & Lewis 2000) beginning in early
fall. e more northerly Pennsylvania (Butler Co.) E. corrusca (pers. obs.) appears
to share the overwintering habit of the Massachusetts rey. In contrast, Hackett
et al. (1996) mention collecting E. corrusca in late winter 1983 “while they were
emerging from their overwintering sites at the base of a white oak tree in Belts-
ville, Maryland.” e more southern Maryland E. corrusca’s sudden appearance at
winter’s end more closely parallels the TN E. corrusca habit. Further studies are
needed to determine whether these regional dierences in emergence and overwin-
tering behaviours suggest distinct species, univoltine vs. semivoltine life cycles
perhaps inuenced by the milder climatic conditions in TN, or adaptive behaviours
governed by winter conditions and predation risks for dierent locales. Since E.
corrusca are a species complex (Fender 1970) instead of a distinct species, deter-
mining dierences in larval development, adult size variations, overwintering
habits and adult emergence times could help in species discrimination. No adults
Lampyrid Volume 2 (2012)
OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 67
have yet been observed feeding in TN at sap ows or on owers as they have in the
more northern range. Perhaps the arboreal overwintering habit of the MA adults
requires more energy. Captive TN E. corrusca will however, feed from an apple slice,
sometimes choosing the apple over mating.
e clear drops of liquid that both sexes deposit from their terminal segment
when disturbed and/or climbing are in addition to the white beads of reexive
bleeding previously noted and described (Williams 1917; Rooney & Lewis 2000,
respectively). is clear liquid may be excreta, or a chemical cue promoting sexual
or social communication. e vertical upward migration on the days of initial
emergence (Fig. 7) suggests these reies are following one another up a particular
route of each tree and that something more than just the direction and heat from
the sun inuences this route
Further studies could focus on what actually occurs during the quiescent 4-6 wk
aer initial appearance but before ight and coupling. What is observed is that they
search the trunk or rest head down in the furrows and in the later weeks of quies-
cence, disappear into the canopy. e MA E. corrusca are known to be sexually
mature early in the season (Rooney & Lewis 2000) so perhaps unseen pre-ight
coupling is occurring in the canopy. Pre-ight mating, if true, would also reduce
risks associated with ight, e.g., exposure to the elements and predators, for these
weak yers.
Additional discussion for Pyractomena borealis
e ‘ckle’ behaviour of larvae in their constant search for a better pupation site
has also been observed previously (Lloyd 1997). TN larvae were especially mobile
when rst climbing in January and February and oen changed locations but not
trees before settling on a permanent pupation site usually by late February or early
March. Some larvae may disappear above the surveyed 3 m mark, where others
succumb to predation or the elements. Larvae pupated < 2 m high on the only two
smooth but stringy barked trees, yet the scaliest, roughest trees that are harder to
climb oen had pupation sites as high as 3m, a counter-intuitive nding. Further
study is needed to determine if TN larvae choose only furrowed trees for pupation,
or pupate out of sight above 3 m on rough and smooth-barked trees. Red and sugar
maples (Acer rubrum and Acer saccharum), which are smooth-barked species
until extreme age, are the most common trees in the local forests (Oswalt 2007)
comprising 17% of all stems >2.5cm dbh, yet P. borealis have not been found on any
maples (Fig. 3). Instead, 90% of pupae are found on poplars, oaks, hickories and
walnuts whose combined species comprise only 21% of the forest (Fig. 3).
Larvae avoid most of the forest oor vegetation that shades the lower tree trunks
by climbing up the trunk 1-2 m into the more direct warming rays of the sun.
Climbing higher has also been proposed as means to stay above high water levels
in ood-prone, low-lying forests in FL where P. borealis is found (Lloyd 1997). is
may also apply to the P. borealis that colonise trees in the alluvial forests in TN,
Lampyrid Volume 2 (2012)
68 FAUST
though many of the preferred trees are located on high ground.
at the male larvae climb, attach, pupate and eclose earlier in the wild on
average than females concurs with ndings from a previous laboratory study
(Gentry 2003) where pupal durations were determined at constant temperatures.
Findings of Al-Saar et al. (1996) and Weston and Diaz (2005) indicate that varying
temperatures can actually enhance maturation in some insect species. Could it
be possible that the males obtain further developmental advantage by climbing
and pupating earlier in the season when the temperatures are more extreme and
variable? Is it possible that the guarding males provide some measure of thermal
protection to their tended female pupae thus inuencing female development (Figs.
10 & 11)?
Protandry gives the males much time to locate and guard potential mates, which
are oen coupled immediately aer the female’s eclosion. is diurnal mating
strategy, taking place during the relative warmth of the day, bypasses ash commu-
nication and may be an important adaptation to the nighttime conditions that are
oen unfavorable to courtship displays. Locating females without needing to y
or ash may increase males’ mating success and reserve their energy for photic
display on the few warm nights available when ight conditions are ideal. is dual
strategy approach ensures the males will have mating opportunities regardless of
the unpredictable late winter/early spring weather. While eclosing virgin females
had little control over mate choice, in rematings, depending on the situation and the
male, females displayed both acquiescent and eective avoidance behaviours. e
prolonged (up to 8 days) copulatory mate-guarding seen in P. borealis is common in
insects and is a male adaptation to avoid sperm competition (Tompkins & Simmons
2000).
Future
In the past 19 years, the Knox reies have faced many challenges aecting their
once dark, forested rural habitat. e clearing of forested areas that the reies
inhabit and in which they display is a major threat, with 15% of the primary Knox
site lost in the past four years alone. While daytime mating incidentally precludes
E. corrusca from the negative eects of articial lighting, the nocturnal courtship
phase of P. borealis is not spared. Homes that have been built in these areas have
introduced light pollution and pollution from landscaping agrochemicals that
may be contributing to the apparent decline in rey populations. New shopping
centers, a football stadium and schools built less than 2 km away now illumi-
nate the night skies to the point that a ashlight is no longer necessary on some
nights while walking the rey survey trails. Habitat loss and light pollution are
also serious threats to Asian rey populations (Wong 2009; Nada et al. 2009) and
reies worldwide. Other imminent threats to the TN reies concern threats to
their colony trees. In addition to natural mortality each year due to high winds,
disease and lightning, the invasive kudzu vine Pueraria lobata threatens to smother
Lampyrid Volume 2 (2012)
OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 69
many of the preferred and colony trees. e ousand Cankers disease (Geosmitha
spp.) that is spread by the walnut twig beetle, Pityophthorus juglandis (Coleop-
tera: Scolytidae) and is deadly to black walnuts, has recently been found infesting
walnuts in TN (M.T. Windham, pers. comm., August 2010).
Future studies of mechanisms governing the abrupt appearance and vertical
mass tracking up colony trees might provide new understanding of chemical
cues, early season adaptations and regional dierences in behaviour of the E.
corrusca complex. e described observations of male P. borealis daytime search
- and guard-behaviour of larva/pupal females, their copulation without courtship
dialogue early in the mating season, and their nocturnal habits and ash displays in
the latter half of the season, provide a rst insight into a dual mating strategy of a
lampyrid. With their preference for trees of a certain size, furrow depth, species and
specic location, both of these adaptable, hardy rey species nonetheless remain
vulnerable to natural and man-made changes to their environments. It is hoped
these studies will further the appreciation of the importance of individual trees
and habitat to the survival and health of larval, pupal and adult rey populations
and increase the understanding of these two species’ remarkable adaptations to the
habitat and climatic extremes of the early season.
ACKNOWLEDGEMENTS
My thanks to the hosts and sponsors of the 2010 International Firey Sympo-
sium held in Selangor, Malaysia for providing such a wonderful opportunity for
cooperation, collaboration, learning and sharing of information on the world of
reies. Special appreciation goes to the Forest Research Institute of Malaysia and
the Malaysian Nature Society. anks to Edgar Faust and Richard Evans for tree
details, to Ted Faust and Paul Weston for technical assistance, Haden Wesley and
Martie Wood for help in the eld and e Great Smoky Mountains National Park
(permit #FaustGRSM2009-SCI-0026) for access to two study sites.
REFERENCES
A-S, Z., G, J.  A, J. (1996) Temperature and humidity
aecting development, survival and weight loss of the pupal stage of Drosophila
melanogaster and the inuence of alternating temperature on the larvae. Journal
of ermal Biology 21 389-396.
A, M.  B, M. (1998) Description of the preimaginal stages
of Pyractomena borealis (Randall, 1838), and notes on its biology (Coleoptera:
Lampyridae). Proceedings of the Washington Entomological Society 100 421-430.
B, Y. (1991) Checklist of Beetles of Canada and Alaska. Ottawa: Canada
Communication Group. 430 pp.
B, B.V. (1994) Life history parameters and new host records of phorid (Diptera:
Phoridae) parasitoids of reies. Coleopterists Bulletin 48 145-147.
Lampyrid Volume 2 (2012)
70 FAUST
B, L. (1974) Flash behaviour of a Nova Scotian rey Photuris fairchildi
(Barber) during courtship and aggressive mimicry. Coleopterists Bulletin 28 27-31.
B, L. (1984) Biology of the rey Pyractomena lucifera (Coleoptera:
Lampyridae). Florida Entomologist 67 529-542.
F, L. (2004) Fireies as a catalyst for science education. Integrative and Compar-
ative Biology 44 264-265.
F, L.  W, P. (2009) Degree-day prediction of adult emergence of the
rey Photinus carolinus. Environmental Entomology 38 1505-1512.
F, L.F. (2010) Natural history and ash repertoire of the synchronous rey
Photinus carolinus (Coleoptera: Lampyridae) in the Great Smoky Mountains
National Park. Florida Entomologist 93 208-217.
F, K.M. (1970) Ellychnia of western North America. Northwest Science 44
31-43.
F, J.D. (2009) Downscaling climate over complex terrain: high ne-scale
spatial variation of near-ground temperatures in a montane forested landscape
(Great Smoky Mountains, USA). Journal of Applied Meteorology and Climatology
48 1033-1049.
G, E. (2003) On sexual selection in Florida's Pyractomena borealis (Coleop-
tera: Lampyridae). Florida Entomologist 86 114-123.
G, J. (1957) Revision of the Nearctic species of Pyractomena (Coloeoptera:
Lampyridae). Wasmann Journal of Biology 15 237-284.
H, K.J., W, R.F., F, F.E., T, J.G., G, G.E., R,
D.L., C, P., B, J.M., H, R.B., C, T.B., K, M., C, E.A.
W, D.L. (1996) Spiroplasma corruscae sp. nov., from a rey beetle
(Coleoptera: Lampyridae) and tabanid ies (Diptera: Tabanidae). International
Journal of Systematic Bacteriology 46 947-950.
J, G., K, T., P, H., C, J., H, S., K, W., C, Y., L, K., P,
I., S, H. K, J. (2009) Wolbachia infection in the Korean endemic rey,
Luciola unmunsana (Coleoptera: Lampyridae). Journal of Asia-Pacic Entomology
12 33-36.
J, W.F.A.W, H, N.R.  I, Z.Z. (2010) Firey distribution and
abundance on mangrove vegetation assemblages in Sepetang estuary, Peninsular
Malaysia. Wetlands Ecology and Management 18 367-373.
L, S.  W, O. (1991) Reproductive ecology of two species of Photinus
reies (Coleoptera: Lampyridae). Psyche 98 293-307.
L, S.M.  C, C.K. (2008) Flash signal evolution, mate choice and preda-
tion in reies. Annual Review of Entomology 53 293-321.
L, J.E. (1973) Firey parasites and predators. Coleopterists Bulletin 27 91-106.
L, J.E. (1997) On research and entomological education, and a dierent light in
the lives of reies (Coleoptera: Lampyridae: Pyractomena). Florida Entomologist
80 120-131.
M, A. (2006) National Park Service. Great Smoky Mountains National Park.
Lampyrid Volume 2 (2012)
OBSERVATIONS ON E. CORRUSCA & P. BOREALIS 71
Gatlinburg, Tennessee. Discover Life in America (DLIA). All Taxa Biodiver-
sity Inventory. http://www.dlia.org/atbi/species/Animalia/Arthropoda/Insecta/
Coleoptera/Elateroidea/Lampyridae.
M, M. (2010) Firey night time assessment in Niah River. Sarawak Fireies.
http://sarawakfireflies.blogspot.com/2010/01/firef ly-night-time-assessment-in-
niah.html.
N, B., K, L., N-R, Y.  K, V. (2009) Conservation eorts
for the synchronous reies of the Selangor River in Malaysia. In Diversity and
Conservation of Fireies. Proceedings of the International Symposium on Diver-
sity and Conservation of Fireies, Queen Sirikit Botanic Garden, Chiang Mai,
ailand, 26-30 August 2008 (Ed. by Napompeth, B.), pp. 160-171. Chiang Mai:
Queen Sirikit Botanic Garden.
NOAA (National Oceanic and Atmospheric Agency). (2008-2010) http://www.cpc.
noaa.gov/products/analysis_monitoring/cdus/degree_days/grodgree.txt.
NRCC (Northeast Regional Climate Center). (2008-2010) http://climod.nrcc.
cornell.edu/climod/dd/.
O, N.  W, C.H. (2012) Observations on the external morphology and
behaviour of Pteroptyx tener and Pteropytx bearni in Malaysia. In: Firey Conser-
vation: From Science to Practice. Proceedings of the Second International Firey
Symposium, Selangor, Malaysia, 2-5 August 2010 (Ed. by Kirton, L.G., Lim, G.T. &
Day, J.C.). Lampyrid 2 80-86.
O, C. (2007) Forest Composition of Oak-hickory Forest Type. USDA Forest
Service, Southern Research Station, Forest Inventory and Analysis Program.
R, J. L, S. (2000) Notes on the life history and mating behaviour of
Ellychnia corrusca (Coleoptera: Lampyridae). Florida Entomologist 83 324-334.
T, J. S, L.W. (2000) Sperm competition games played by dimor-
phic male beetles: fertilization gains with equal mating access. Proceedings of
Royal Society of London B 267 1547-1553.
W, J.H., Z, W.  G, L.R. (1995) Evolution and phylogeny of Wolbachia:
reproductive parasites of arthropods. Proceedings of Royal Society of London B 261
55-71.
W, P.  D, M. (2005) ermal requirements and development of immature
stages of Viburnum leaf beetle, Pyrrhalta viburni (Paykull) (Coleoptera: Chrys-
omelidae). Environmental Entomology 34 985-989.
W, F.X. (1917) Notes on the life-history of some North American Lampy-
ridae. Journal New York Entomology Society 25 11-13.
W, C.H. (2009) Firey watching and conservation in involving local commu-
nities in Malaysia. In: Diversity and Conservation of Fireies. Proceedings of the
International Symposium on Diversity and Conservation of Fireies, Queen Sirikit
Botanic Garden, Chiang Mai, ailand, 26-30 August 2008 (Ed. by Napompeth,
B.), pp. 141-148. Chiang Mai: Queen Sirikit Botanic Garden.
  • ... Aspects of the winter ecology of the Winter Firefly are well-documented (Faust 2012, Rooney and Lewis 2000, Williams 1917, particularly its reproductive phenol- ogy. In northeastern Massachusetts, Winter Firefly adults appear from late-summer through autumn on tree bark (Fig. 1A), where they overwinter ( Rooney and Lewis 2000). ...
    ... In the fall, the recently emerged adults have substantial fat reserves, but no internal evidence of sexual maturation (Rooney and Lewis 2000). Adult Winter Fireflies in eastern Tennessee typically appear on tree trunks from Octo- ber to February, depending on conditions during the previous larval growing season, with mating and dispersal starting in mid-March (Faust 2012(Faust , 2017. Considering that the Winter Firefly's diurnal mating behavior deviates from the typical noctur- nal courtship and mating of fireflies, it is not surprising that adults lack a light organ (Stanger-Hall et al. 2007) and apparently rely on pheromonal signaling (Ming andLewis 2010, South et al. 2008), as do other diurnal lampyrids (Lloyd 1972). ...
    ... Such protection might be particularly important to the Winter Firefly, given its extreme levels of LBGs ( Smedley et al. 2017). Although its phenological shift is not as pronounced as that of the Winter Firefly, Pyractomena borealis (Randall) employs a combination of diurnal and nocturnal adult behavior (Faust 2012) and is reproductively active largely before the appearance of Photuris. We have recently detected LBGs in this species (S.T. Deyrup et al., unpubl. ...
    Article
    Ellychnia corrusca (Winter Firefly) is one of few winter-active insects. Exposed throughout the season, this beetle appears vulnerable to insectivorous predators, but was recently shown to possess lucibufagins (LBGs), potent chemical defenses. The Winter Firefly is closely related to summer-active fireflies. To provide an adaptive explanation for this apparent phenological shift, we hypothesized that winter activity may protect the Winter Firefly from summer-active fireflies in the genus Photuris, predators that specialize on LBG-containing prey. To test this hypothesis, we studied the Winter Firefly and Photuris that occur sympatrically, but asynchronously as adults, at our Connecticut field sites. Through 2 experiments, we demonstrated that Photuris selectively consumes the Winter Firefly and sequesters its LBGs. Our findings are consistent with a hypothesis that winter activity by the Winter Firefly, by enabling early spring reproduction, provides phenological escape from a specialist predator.
  • ... where A f is the number of adult females emerging in a given year, a is a constant expressing how efficient the males are in finding females, and t m is the time needed per copulation. a, the efficiency of males finding females, can be affected by a variety of factors including population density, operational sex ratio, temperature, wind, and precipitation (Faust, 2012). h f is the proportion of females harvested, and is the timing of harvest. ...
    ... For instance, in the case of Photinus pyralis we assumed that the most critical phase in the species' life cycle is during summer, when males search for females to mate with. In 'poor' breeding seasons, which are characterized by cold, rainy weather during early summer or hot, dry weather during late sum- mer, activity of males declines causing fewer females to be mated (Faust, 2010(Faust, , 2012; S. Lewis pers. obs.). ...
  • ... where A f is the number of adult females emerging in a given year, a is a constant expressing how efficient the males are in finding females, and t m is the time needed per copulation. a, the efficiency of males finding females, can be affected by a variety of factors including population density, operational sex ratio, temperature, wind, and precipitation ( Faust, 2012). h f is the proportion of females harvested, and is the timing of harvest. ...
    ... For instance, in the case of Photinus pyralis we assumed that the most critical phase in the species' life cycle is during summer, when males search for females to mate with. In 'poor' breeding seasons, which are characterized by cold, rainy weather during early summer or hot, dry weather during late summer, activity of males declines causing fewer females to be mated ( Faust, 2010Faust, , 2012; S. Lewis pers. obs.). ...
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    The winter firefly (Ellychnia corrusca) is common throughout the eastern United States and Canada. It is notable among fireflies (Coleoptera: Lampyridae) for its adult activity during the winter and early spring months, and for its lack of a light-producing organ. Multiple lines of evidence suggest that E. corrusca is chemically protected, specifically its unusual phenology which results in prolonged exposure to predators, its aposematic coloration, its reflex bleeding upon disturbance, and its relatedness to toxic firefly genera. Chemical investigation of this species revealed the presence of large quantities (>500 μg/beetle) of steroidal pyrones known as lucibufagins. The structures of these lucibufagins were determined using 1D and 2D NMR spectroscopy along with UHPLC-HRMS. Four of these compounds were previously detected in fireflies of the genus Photinus, while the remaining four, which contain a highly modified D-ring of the steroid core, are previously unknown. Analysis of reflex bleeding showed that the hemolymph contained the lucibufagins and that it was primarily released via a band of cuticular pores along the costal margin of the elytra. In addition, our analysis of the eggs, larva, and pupa established that all immature stages possess lucibufagins, thus representing the first instance of a firefly species for which all life stages have been investigated chemically.
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    Research at institutions of higher education could be restored to at least a shadow of its original role through publication in a manner appropriate for immediate classroom use, with questions that pique and direct the interests and activities of students. Studies on basic natural history may be good candidates for such publication and an example is drawn from fireflies: Two woodland species show directional orientation in their pupation sites on the trunks of trees; one uses southerly exposure and the other occurs on the north side of smaller trees, and much lower on the trunks. These contrasting positions have different thermal consequences, as demonstrated with a physical model, which possibly have a role in reducing interspecific sexual contact or prey competition. /// La investigación en instituciones de educación avanzada podría ser restaurada parcialmente a su rol original a traves de publicaciones, de manera tal que las mismas puedan ser usadas para enseñar, con preguntas que atraigan el interés de estudiantes y que se relacionen con sus actividades. Los estudios de historia natural básica pueden ser buenos candidatos para ese tipo de publicaciones, y un ejemplo del mismo se puede obtener con luciérnagas: Dos especies de luciérnagas muestran diferencias en la ubicación de sus pupas en los troncos de los árboles; una especie las ubica expuestas hacia el sur y la otra usa el lado norte de árboles mas pequeños y en la zona mas baja del tronco. Estas posiciones contrastantes tienen diferentes consecuencias térmicas, como se demuestra con un modelo físico, las cuales podrían tener un papel en reducir el contacto sexual o la competencia por alimento entre las dos especies.
  • Article
    Landscape-driven microclimates in mountainous terrain pose significant obstacles to predicting the response of organisms to atmospheric warming, but few if any studies have documented the extent of such finescale variation over large regions. This paper demonstrates that ground-level temperature regimes in Great Smoky Mountains National Park (Tennessee and North Carolina) vary considerably over fine spatial scales and are only partially linked to synoptic weather patterns and environmental lapse rates. A 120-sensor network deployed across two watersheds in 2005-06 exhibited finescale (,1000-m extent) temperature differences of over 2*C for daily minima and over 4*C for daily maxima. Landscape controls over minimum temperatures were associated with finescale patterns of soil moisture content, and maximum temperatures were associated with finescale insolation differences caused by topographic exposure and vegetation cover. By linking the sensor array data to 10 regional weather stations and topographic variables describing site radiation load and moisture content, multilevel spatial models of 30-m resolution were constructed to map daily temperatures across the 2090-km2 park, validated with an independent 50-sensor network. Maps reveal that different landscape positions do not maintain relative differences in temperature regimes across seasons. Near-stream locations are warmer in the winter and cooler in the summer, and sites of low elevation more closely track synoptic weather patterns than do wetter high-elevation sites. This study suggests a strong interplay between near-ground heat and water balances and indicates that the influence of past and future shifts in regional temperatures on the park's biota may be buffered by soil moisture surfeits from high regional rainfall.